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authorZhang, Yanmin <yanmin.zhang@intel.com>2006-02-03 06:04:36 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-03 11:32:09 -0500
commit69dcc99199fe29b0a29471a3488d39d9d33b25fc (patch)
tree4232ad9a782dee6abfe7fa20c95a49249195de8f /drivers/base
parent66ac5a294db70aa377c0d7bbdb0c4e3ef2349b7b (diff)
[PATCH] Export cpu topology in sysfs
The patch implements cpu topology exportation by sysfs. Items (attributes) are similar to /proc/cpuinfo. 1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: represent the physical package id of cpu X; 2) /sys/devices/system/cpu/cpuX/topology/core_id: represent the cpu core id to cpu X; 3) /sys/devices/system/cpu/cpuX/topology/thread_siblings: represent the thread siblings to cpu X in the same core; 4) /sys/devices/system/cpu/cpuX/topology/core_siblings: represent the thread siblings to cpu X in the same physical package; To implement it in an architecture-neutral way, a new source file, driver/base/topology.c, is to export the 5 attributes. If one architecture wants to support this feature, it just needs to implement 4 defines, typically in file include/asm-XXX/topology.h. The 4 defines are: #define topology_physical_package_id(cpu) #define topology_core_id(cpu) #define topology_thread_siblings(cpu) #define topology_core_siblings(cpu) The type of **_id is int. The type of siblings is cpumask_t. To be consistent on all architectures, the 4 attributes should have deafult values if their values are unavailable. Below is the rule. 1) physical_package_id: If cpu has no physical package id, -1 is the default value. 2) core_id: If cpu doesn't support multi-core, its core id is 0. 3) thread_siblings: Just include itself, if the cpu doesn't support HT/multi-thread. 4) core_siblings: Just include itself, if the cpu doesn't support multi-core and HT/Multi-thread. So be careful when declaring the 4 defines in include/asm-XXX/topology.h. If an attribute isn't defined on an architecture, it won't be exported. Thank Nathan, Greg, Andi, Paul and Venki. The patch provides defines for i386/x86_64/ia64. Signed-off-by: Zhang, Yanmin <yanmin.zhang@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/Makefile1
-rw-r--r--drivers/base/topology.c148
2 files changed, 149 insertions, 0 deletions
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index f12898d53078..e99471d3232b 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -8,6 +8,7 @@ obj-y += power/
8obj-$(CONFIG_FW_LOADER) += firmware_class.o 8obj-$(CONFIG_FW_LOADER) += firmware_class.o
9obj-$(CONFIG_NUMA) += node.o 9obj-$(CONFIG_NUMA) += node.o
10obj-$(CONFIG_MEMORY_HOTPLUG) += memory.o 10obj-$(CONFIG_MEMORY_HOTPLUG) += memory.o
11obj-$(CONFIG_SMP) += topology.o
11 12
12ifeq ($(CONFIG_DEBUG_DRIVER),y) 13ifeq ($(CONFIG_DEBUG_DRIVER),y)
13EXTRA_CFLAGS += -DDEBUG 14EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
new file mode 100644
index 000000000000..915810f6237e
--- /dev/null
+++ b/drivers/base/topology.c
@@ -0,0 +1,148 @@
1/*
2 * driver/base/topology.c - Populate sysfs with cpu topology information
3 *
4 * Written by: Zhang Yanmin, Intel Corporation
5 *
6 * Copyright (C) 2006, Intel Corp.
7 *
8 * All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
18 * NON INFRINGEMENT. See the GNU General Public License for more
19 * details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 *
25 */
26#include <linux/sysdev.h>
27#include <linux/init.h>
28#include <linux/mm.h>
29#include <linux/cpu.h>
30#include <linux/module.h>
31#include <linux/topology.h>
32
33#define define_one_ro(_name) \
34static SYSDEV_ATTR(_name, 0444, show_##_name, NULL)
35
36#define define_id_show_func(name) \
37static ssize_t show_##name(struct sys_device *dev, char *buf) \
38{ \
39 unsigned int cpu = dev->id; \
40 return sprintf(buf, "%d\n", topology_##name(cpu)); \
41}
42
43#define define_siblings_show_func(name) \
44static ssize_t show_##name(struct sys_device *dev, char *buf) \
45{ \
46 ssize_t len = -1; \
47 unsigned int cpu = dev->id; \
48 len = cpumask_scnprintf(buf, NR_CPUS+1, topology_##name(cpu)); \
49 return (len + sprintf(buf + len, "\n")); \
50}
51
52#ifdef topology_physical_package_id
53define_id_show_func(physical_package_id);
54define_one_ro(physical_package_id);
55#define ref_physical_package_id_attr &attr_physical_package_id.attr,
56#else
57#define ref_physical_package_id_attr
58#endif
59
60#ifdef topology_core_id
61define_id_show_func(core_id);
62define_one_ro(core_id);
63#define ref_core_id_attr &attr_core_id.attr,
64#else
65#define ref_core_id_attr
66#endif
67
68#ifdef topology_thread_siblings
69define_siblings_show_func(thread_siblings);
70define_one_ro(thread_siblings);
71#define ref_thread_siblings_attr &attr_thread_siblings.attr,
72#else
73#define ref_thread_siblings_attr
74#endif
75
76#ifdef topology_core_siblings
77define_siblings_show_func(core_siblings);
78define_one_ro(core_siblings);
79#define ref_core_siblings_attr &attr_core_siblings.attr,
80#else
81#define ref_core_siblings_attr
82#endif
83
84static struct attribute *default_attrs[] = {
85 ref_physical_package_id_attr
86 ref_core_id_attr
87 ref_thread_siblings_attr
88 ref_core_siblings_attr
89 NULL
90};
91
92static struct attribute_group topology_attr_group = {
93 .attrs = default_attrs,
94 .name = "topology"
95};
96
97/* Add/Remove cpu_topology interface for CPU device */
98static int __cpuinit topology_add_dev(struct sys_device * sys_dev)
99{
100 sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
101 return 0;
102}
103
104static int __cpuinit topology_remove_dev(struct sys_device * sys_dev)
105{
106 sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
107 return 0;
108}
109
110static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
111 unsigned long action, void *hcpu)
112{
113 unsigned int cpu = (unsigned long)hcpu;
114 struct sys_device *sys_dev;
115
116 sys_dev = get_cpu_sysdev(cpu);
117 switch (action) {
118 case CPU_ONLINE:
119 topology_add_dev(sys_dev);
120 break;
121 case CPU_DEAD:
122 topology_remove_dev(sys_dev);
123 break;
124 }
125 return NOTIFY_OK;
126}
127
128static struct notifier_block topology_cpu_notifier =
129{
130 .notifier_call = topology_cpu_callback,
131};
132
133static int __cpuinit topology_sysfs_init(void)
134{
135 int i;
136
137 for_each_online_cpu(i) {
138 topology_cpu_callback(&topology_cpu_notifier, CPU_ONLINE,
139 (void *)(long)i);
140 }
141
142 register_cpu_notifier(&topology_cpu_notifier);
143
144 return 0;
145}
146
147device_initcall(topology_sysfs_init);
148